德鲁德分布非均匀膜的光学特性模拟分析

从德鲁德理论出发,对多元共蒸法镀制的非均匀膜的折射率分布与沉积速率的关系进行了探讨;然后利用计算机辅助模拟,对德鲁德分布非均匀光学薄膜,从单周期和多周期、正变和负变、完整周期和存在半周期几个方面对其光学特性进行了系统分析.研究发现：其透射率的极小值和周期数的关系遵从周期数的三次多项式衰减规律,不同规律的德鲁德分布非均匀膜可用来设计不同功能的滤光片.     

Extended Bose-Hubbard model with pair hopping on triangular lattice

We study systematically an extended Bose-Hubbard model on the triangular lattice by means of a meanfield method based on the Gutzwiller ansatz. Pair hopping terms are explicitly included and a three-body constraint is applied. The zero-temperature phase diagram and a variety of quantum phase transitions are investigated in great detail. In particular, we show the existence and the stability of the pair supersolid phase.     

Rheological Behaviors of Polypropylene/Poly(1-butene) Blends

The rheological behaviors of polypropylene (PP)/poly(1-butene) (PB) blends with homo-polypropylene (PP₁) or impact polypropylene (PP₂), a poly(propylene-co-ethylene) as the PP component were studied. With increasing of PB resin content for both PP/PB blends, the blends showed higher G'(ω), G''(ω) and η*(ω) at low frequencies but lower values at high frequencies which implied that the processability was improved. A two-phase morphology was observed through the various rheological responses, including G'(ω)-ω terminal region curves, Cole-Cole plots and the weighted relaxation spectra with the PB contents up to 40?wt%. With the same PB content, the rheological parameters of the PP₂/PB blends were quite different from those of the PP₁/PB, which can be attributed to the stronger interaction between PB chains and the ethylene-co-propylene copolymer in PP₂. The impact strength of the PP₂/PB blends was improved dramatically over that of the PP₁/PB. The more significant toughening effect for the PP₂/PB blends can be attributed to the special responses of its rheological behaviors.     

Optical properties and structures of silver thin films deposited by magnetron sputtering with different thicknesses

A series of thin Ag films with different thicknesses grown under identical conditions are analyzed by means of spectrophotometer. From these measurements the values of refractive index and extinction coefficient are calculated. The films are deposited onto BK7 glass substrates by direct current (DC) magnetron sputtering. It is found that the optical properties of the Ag films can be affected by films thickness.Below critical thickness of 17 nm, which is the thickness at which Ag films form continuous films, the optical properties and constants vary significantly with thickness increasing and then tend to a stable value up to about 40 nm. At the same time, X-ray diffraction measurement is carried out to examine the microstructure evolution of Ag films as a function of films thickness. The relation between optical properties and microstructure is discussed.     

Ignition delay times of methane and hydrogen highly diluted in carbon dioxide at high pressures up to 300 atm

The need for more efficient power cycles has attracted interest in super-critical CO₂ (sCO₂) cycles. However, the effects of high CO₂ dilution on auto-ignition at extremely high pressures has not been studied in depth. As part of the effort to understand oxy-fuel combustion with massive CO₂ dilution, we have measured shock tube ignition delay times (IDT) for methane/O₂/CO₂ mixtures and hydrogen/O₂/CO₂ mixtures using sidewall pressure and OH* emission near 306?nm. Ignition delay time was measured in two different facilities behind reflected shock waves over a range of temperatures, 1045–1578?K, in different pressures and mixture regimes, i.e., CH₄/O₂/CO₂ mixtures at 27–286 atm and H₂/O₂/CO₂ mixtures at 37–311 atm. The measured data were compared with the predictions of two recent kinetics models. Fair agreement was found between model and experiment over most of the operating conditions studied. For those conditions where kinetic models fail, the current ignition delay time measurements provide useful target data for development and validation of the mechanisms.     

水杨醛类希夫碱在LB膜上的光谱性能的研究

合成了两种末端碳锭长度不同的水杨醛类希夫碱N-十二烷基（2-羟基-5-硝基苯甲亚胺）和N-十六烷基（2-羟基-5-硝基苯甲亚胺），研究了它们在气-液界面上的成膜性能，并通过紫外、荧光、红外显微镜等光谱手段对它们在LB膜上的性能进行了表征。实验结果表明两种希夫碱分子在LB膜中都形成了J-聚体，末端碳链较长的希夫碱 成膜性能相对较好，并且在膜上也能光致发光，但希夫碱分子的LB膜存在一定的缺陷。     

Influence of Cr interlayer on the structure and optical properties of Ag films on glass substrate by magnetron sputtering

Optical properties and microstructure of Ag film on glass substrate with Cr intermediate layer were studied by using spectrophotometer and XRD. The spectra results showed that introducing Cr intermediate layer reduced the surface roughness and promoted the reflectivity of Ag film. The XRD analysis showed that the crystalline grains increased and the stress decreased. The adhesion was also improved by using the tape test method.     

微纳光纤布拉格光栅折射率传感特性研究

利用光纤布拉格光栅方程和光纤基模有效折射率随纤芯半径和环境折射率的函数关系, 建立了微纳光纤布拉格光栅(MNFBG)反射波长随环境折射率变化的数学模型, 给出了波长灵敏度函数, 并指出MNFBG反射波长的变化规律决定于有效折射率随纤芯半径和环境折射率变化的关系. 详细探究了有效折射率及其灵敏度的变化规律, 结果表明: 有效折射率随纤芯半径和环境折射率的减小而非线性减小, 其对环境折射率变化的灵敏度随环境折射率的增大而非线性增加, 而且随纤芯半径减小, 有效折射率的灵敏度、线性度以及线性响应范围均呈递增规律. 通过对纤芯半径为0.5 μm的MNFBG在1.20–1.30和1.33–1.43 环境折射率范围内的波长响应关系拟合, 分别获得了477.33 nm/RIU和856.30 nm/RIU的波长灵敏度以及99.58 %和99.7%的高线性度, 论证了分析结论以及折射率区间划分测量方案的正确性, 为MNFBG折射率传感器的设计、优化以及应用提供了参考依据. 关键词： 微纳光纤 光纤布拉格光栅 折射率传感 数值模拟     

Quantum Teleportation of the Two-Qubit Entangled State by Use of Four-Qubit Entangled State

In this article, a scheme for quantum teleportation of a two-qubit entangled state using four-qubit cluster state is discussed by use of cavity quantum electrodynamics (QED) involving the interaction of the atoms with the cavity. In this protocol, by using a one-dimensional maximally four-qubit cluster state as quantum channel, quantum information of an unknown state of two two-level particles is faithfully transmitted from a sender (Alice) to a remote receiver (Bob). According to the results measured by the Bob, as it is shown, the unknown two-particle entangled state can be teleported perfectly, and the successful possibilities and fidelities of the scheme can reach 1.0.     

农村中学实验教学与创新教育的思考

在信息技术和知识经济快速发展的今天，创新已成为民族振兴的关键，国家兴旺的基石．创新教育是现代教育的灵魂，要培养勇于创新的综合型人才，在现代教育中实施创新教育已成为人们的共识．而创新能力的培养，教育起着举足轻重的作用．在教学中应有意识地加强学生的创新意识和创新能力的培养，而中学物理实验教学则在这一培养链条中扮演着不可替代的角色．因此，实验教学在物理教学乃至整个创新教育中具有重要的地位．我们必须以这样的视角，认识目前中学物理实验教学的现状和解决问题的思路．